Object detecting apparatus and irregularity detecting device for the same

Abstract

An object detecting apparatus for detecting an object or a distance with the object includes at least one light receiving element for detecting a light quantity entering from a sensor window portion for example, a projection window portion and an entrance window portion through which an electromagnetic wave from an electromagnetic wave generation portion toward an object and a reflected electromagnetic wave from the object pass. Furthermore, an irregularity determining portion determines a state of at least one of the projection window portion and the entrance window portion using at least the detected light quantity of the light receiving element. For example, the light receiving element includes a first light receiving portion and a second light receiving portion which receive the light quantities of direct current part of light entering from the first and second light receiving portions.

1. An object detecting apparatus for detecting an object or a distance from the object, the object detecting apparatus comprising:
 a case; 
 an electromagnetic wave generation portion disposed in the case to generate and radiate a searching electromagnetic wave; 
 a projection window portion disposed in the case, the projection window portion having a wave passing surface made of a wave permeating material for passing through the searching electromagnetic wave generated from the electromagnetic wave generation portion; 
 an electromagnetic wave receiving portion disposed in the case for receiving a reflected wave of the searching electromagnetic wave, reflected from the object; 
 an entrance window portion disposed in the case, the entrance window portion having a wave passing surface made of a wave permeating material for passing through the reflected wave before being received to the electromagnetic wave receiving portion; 
 a first light receiving element disposed in the case to detect a light quantity of a direct current part of light entering from at least one of the projection window portion and the entrance window portion; and 
 an irregularity determining portion which determines a state of at least one of the projection window portion and the entrance window portion using at least the detected light quantity of the first light receiving element. 
 
   
   
     2. The object detecting apparatus according to  claim 1 , wherein the first light receiving element is disposed in the case to detect the light quantity of the direct current part of light entering from the projection window portion, the apparatus further comprising
 a second light receiving element disposed in the case to detect the light quantity of the direct current part of light entering from the entrance window portion, 
 wherein the irregularity determining portion determines the state of at least one of the projection window portion and the entrance window portion based on the detected light quantity of the first light receiving element and the detected light quantity of the second light receiving element. 
 
   
   
     3. The object detecting apparatus according to  claim 2 , wherein:
 each of the first and second light receiving elements generates an output voltage in accordance with the light quantity of the received direct current part; and 
 the irregularity determining portion determines the state of at least one of the projection window portion and the entrance window portion based on a ratio of the output voltages generated from the first and second light receiving elements. 
 
   
   
     4. The object detecting apparatus according to  claim 1 , further comprising:
 a light receiving window portion provided in the case at a position different from the projection window portion and the entrance window portion to pass through the direct current part of light from an exterior of the case; and 
 a second light receiving element disposed in the case to detect a light quantity of the direct current part of light entering from the light receiving window portion, 
 wherein the irregularity determining portion determines the state of one of the projection window portion and the entrance window portion based on the detected light quantity of the first light receiving element and the detected light quantity of the second light receiving element. 
 
   
   
     5. The object detecting apparatus according to  claim 4 , wherein the first light receiving element detects the light quantity entering from the projection window portion. 
   
   
     6. The object detecting apparatus according to  claim 1 , further comprising
 a light quantity detecting unit disposed outside the case to detect a light quantity, 
 wherein the irregularity determining portion determines the state of at least one of the projection window portion and the entrance window portion based on the detected light quantity of the first light receiving element and the detected light quantity of the light quantity detecting unit. 
 
   
   
     7. The object detecting apparatus according to  claim 1 , wherein the irregularity determining portion is provided in a control portion inside the case. 
   
   
     8. The object detecting apparatus according to  claim 1 , wherein the case is disposed in a vehicle so as to detect the object near the vehicle or a distance between the vehicle and the object. 
   
   
     9. An object detecting apparatus according to  claim 1 , wherein the irregularity determining portion determines a dirt state of at least one of the projection window portion and the entrance window portion. 
   
   
     10. An object detecting apparatus for detecting an object or a distance from the object, the object detecting apparatus comprising:
 a case; 
 an electromagnetic wave generation portion disposed in the case to generate and radiate a searching electromagnetic wave; 
 a projection window portion disposed in the case, the projection window portion having a wave passing surface made of a wave permeating material for passing through the searching electromagnetic wave generated from the electromagnetic wave generation portion; 
 an electromagnetic wave receiving portion disposed in the case for receiving a reflected wave of the searching electromagnetic wave, reflected from the object; 
 an entrance window portion disposed in the case, the entrance window portion having a wave passing surface made of a wave permeating material for passing through the reflected wave before being received to the electromagnetic wave receiving portion; 
 a light receiving element disposed in the case at a position where a direct current part of light entering from at least one of the projection window portion and the entrance window portion is restricted to be received, so as to detect a scattering light part of the direct current part, which generates when dirt adheres on at least one of the projection window portion and the entrance window portion; and 
 an irregularity determining portion which determines a state of at least one of the projection window portion and the entrance window portion using the detected light quantity of the light receiving element. 
 
   
   
     11. An irregularity detecting device for an object detecting apparatus including a sensor window portion through which an electromagnetic wave from an electromagnetic wave generating portion toward an object and a reflected electromagnetic wave from the object pass, the irregularity detecting device comprising:
 a light receiving element disposed to detect a light quantity entering from the sensor window portion; and 
 an irregularity determining portion which determines a state of the sensor window portion using the detected light quantity of the light receiving element. 
 
   
   
     12. The irregularity detecting device according to  claim 11 , wherein:
 the light receiving element includes a first light receiving portion and a second light receiving portion which receive the light quantities of direct current part of light entering from different positions of the sensor window portion; and 
 the irregularity determining portion determines the state of the sensor window portion based on the detected light quantities of the first and second light receiving portions. 
 
   
   
     13. The irregularity detecting device according to  claim 12 , wherein:
 each of the first and second light receiving portions generates an output voltage in accordance with the received light quantity; and 
 the irregularity determining portion determines the state of the search window portion based on a ratio of the output voltages generated from the first and second light receiving portions. 
 
   
   
     14. The irregularity detecting device according to  claim 11 , further comprising:
 a light receiving window portion through which light is entered, the light receiving window portion provided at a position different from the sensor window portion; and 
 an another light receiving element disposed to detect a light quantity entering from the light receiving window portion, 
 wherein the irregularity determining portion determines the state of the sensor window portion based on the detected light quantity of the light receiving element and the detected light quantity of the another light receiving element. 
 
   
   
     15. The irregularity detecting device according to  claim 11 , wherein the light receiving element is disposed in the case at a position where a direct current part of light entering from the sensor window portion is restricted to be received, so as to detect a scattering light part of the direct current part, which generates when an irregularity is present on the sensor window portion. 
   
   
     16. The irregularity detecting device according to  claim 11 , further comprising
 a light quantity detecting unit disposed outside the case to detect a light quantity, 
 wherein the irregularity determining portion determines the state of at least one of the projection window portion and the entrance window portion based on the detected light quantity of the first light receiving element and the detected light quantity of the light quantity detecting unit. 
 
   
   
     17. The irregularity detecting device according to  claim 11 , wherein the irregularity determining portion determines a dirt state of at least one of the projection window portion and the entrance window portion.